(a) Technical Field of the Invention
The present invention generally relates to optical fibers, and more particularly to a coupling assembly comprising coupler and connectors for tight joining of two fiber cables' end surfaces.
(b) Description of the Prior Art
The introduction of fiber optics has dramatically changed how communications is actually conducted. Using lights as carriers and fiber cables to deliver fight signals precisely and accurately, fiber optics provides signal transmissions far superior than conventional means and, therefore, relevant industries have emerged around the field of fiber optics.
In real-life applications, it is often required to join two segments of fiber cables together using passive devices such as couplers. An ideal fiber coupler should be able to provide low power loss, reliability in terms of frequent connection and disconnection, durability under harsh environment, and easy operation. Currently, a common fiber coupler establishes physical contact between two fiber cables by inserting the connectors installed at the ends of the fiber cables into the sleeves inside the coupler. A spring or other similar devices inside the coupler exerts pressure on the connectors or a tenon of the coupler so that the end surfaces of the fiber cables' cores are in close contact with each other, and light signals could thereby be transmitted from one segment of the fiber cables to another.
For example, both the U.S. Pat. No. 5,359,688 and Republic of China Patent No. 302,441 disclose different connector and coupler designs for joining a single pair of fiber cables. The connectors according to these teachings are composed of multiple components arranged in a complicated structure. Not only the installation of the connectors becomes burdensome, but also the coupler requires a larger form factor so as to accommodate the more complicated connectors. In user environments where facility space is tight, the bulky couplers could only provide a limited number of cable couplings.
U.S. Pat. No. 5,719,977 therefore discloses a connector design having a smaller form factor, which is locked to the coupler utilizing the connector's special shape. Compared with conventional connectors and couplers, the design is able to provide an additional pair of fiber cable coupling within the same amount of space. The space saving of the teaching, however, is compromised by the additional requirement of increased precision in the production of the reduced-size components. For example, the diameter of the connector's tubular plug is reduced from the conventional 2.5 mm to 1.25 mm, making the manufacturing process much more difficult and, therefore, increasing the production cost dramatically.
Accordingly, an improved design is required so as to strike a balance between the requirements for scaling down the component sizes and for reducing operation difficulty and production cost.